Guys, would a re-tune be required going from a EC 65mm supercharger pulley to a 178mm crank pulley? I recently did the swap and wanted to make sure I'm getting the benefits. I currently have a tune from EC when I installed the 65mm a couple of years ago. I know the boost and hp numbers are similar between the 2 but wanted to know if there is a difference, if any, between the tunes. Thanks in advance for your input...

 

Here's my take for what it's worth. Unless you are data logging or on a dyno of some kind, it's only a "canned" tune. Meaning info came from someone else's similar mods while being tuned on a dyno. If you want to do a tune, then you have to ask yourself where you are, and you really don't know without the above info. So, you can retune with a canned tune for a 178...but it is what it is... A canned tuned info may not even have been in the same geographical area as well. So, you get what you get. I got a great canned tune for my coupe but until I start data logging I won't know how great...and that should be soon since I am wiring it up now....good luck either way... I personally will never do crank pulleys. Just me...

 

Any reason you're doing the swap since you already have the pulley? What 'benefits' are you referring to? According to EC, the 64.7mm pulley makes more power/boost than even their 181mm crank pulley so if anything you're going to have a slower car with the 178mm while putting everything else in overdrive, I won't ever do a crank pulley either, I don't see any benefits to it over a supercharger pulley, only drawbacks.

 

I switched from a Code 3 to 178 and saw an additional pound of boost and about 10 hp. My Code 3 was sounding like a can of marbles. We'll have to see what the failure rate is on the new pulley's, if any. My prior tune was fine with the switch. Then I put on Needswings manifolds. You MUST retune for the manifolds.

Les

 

74/178 = 18.8psi
65/155 = 18.7psi
physically there shouldnt be anything else going on .....

my2c

 

why the change? is the old sc pulley gone bad? change out the bearing?

 

I had the Code 3 (65mm) for 2 years. I never saw more than 17.9 psi, ever. Multiply all day long and that won't change. I see 19 psi with the 178. This is at 100' above sea level, more or less, and on a 90º day for both. I've never seen evidence of a slipping belt, ever. But I did take the opportunity to instal a PSK with the 178. Just the facts here, no speculation.

Les

 

It's not always the bearing that goes bad.

Les

 

Surely, but was only asking I thought the SC pulleys are better in that way that they are easier to swap and put less stress on the motor.. So why the change to a crank pulley that is... maybe he said it broke,. anyways, do not really know what I want to say here but I hope all goes well. I am just waiting for info on the 61mm sc pulley and tune from Jerr. Nice XMAS gift

 

uuummmm stacking? he happens to have one of the smoothest ramping crank pulleys in the world. fluidamper pulley built by a master machinist

if your tune was good before you will be fine. stack them and retune is mandatory

 

There was no problem with the supercharger pulley...worked and performed just fine. I got my hands on Steve's Renntech fluidamper crank pulley he had on his former SLK32. It's a beautiful and extremely well built piece. I was just curious about the 178 and wanted to try it out, no technical reason why. Just got bored, I guess...may try stacking in the future..

 

ahh ok I see. nice! Stack and get 23,5 psi

On another topic,
How is the Porsche holding up? Any big difference from the XF?
More ladies throwing panties? More HP and wheel spin? better cornering
It is my favourite porsche of all time so i understand the switch. What is the best 1/4 yet?

 

Fubu, sorry if I came across as a dousché. My pulley starting making noise, so I thought, bearing, so I replaced it. Then it was worse. It has a lot of play in the metal straps that attach to the rivets. One pulley isn't better than the other IMO. The supercharger pulley takes 20 minutes to change if you've done it before and have a strap wrench. The crank pulley is meant to be installed and forgot about, well if you have it installed correctly and it's a quality pulley. I take a look at it every few months just to make sure it's not wobbling or anything like that. (too many E55 crank pulley failures)
Glen, I agree with Steve on the tune. If it was spot on for the 65 it's going to be fine for the 178.

Les

 

its a work in progress. main difference from my amg is stick shift, cost to mod can be staggering and wicked fast.
so far 490 rwhp and 502 ft/lbs torque. 11.7 @ 124 mph on sat . thats with street tires 315/25-19 no sticking michelins. i went rwd and now spin thru 4 gears but eliminated the massive wheel hop i was getting. dont want to break 1000$ a piece axles! im working a build plan for the winter that hopefully will get me 575 to 600 rwhp on the stock k24 turbos and a 10 sec timeslip. time will tell
btw in the states panties dont fly into the car they fly out!

 

Thanks for the update bud. Always watch the YouTube clips with amazement.
Would like to see you get into the 10s!
Hmm I did not mention a prepostion buddy here in sweden my ladies dont wear any at all. Shame with red stripes on the suede in the srt sometimes but hey, some sacrifices must be made.

 

Now I get it.....lol....nothing more to say.....lol